Japanese Unexamined, Published Patent Application No. 2000-354969 (paragraphs [0007], [0026] and FIG. 1) describes a grooved grinding wheel in which an abrasive grain layer containing superabrasive grains such as diamond, cubic boron nitride or the like is formed on an outer circumferential surface of a disc-like core drivingly rotatable about an axis and in which oblique grooves having predetermined width and depth are formed on a circumferential grinding surface of the abrasive grain layer to be inclined in a range of 25 degrees through 45 degrees or so relative to the axis of the core. With the grooved grinding wheel like this, it becomes possible to effectively lead coolant along the oblique grooves to a grinding point and to enhance the grinding efficiency by increasing the grinding removal amount as much as about one and a half times in comparison with a grinding wheel with no oblique grooves.
Further, coolant supplied to a grinding point causes a dynamic pressure to be generated between a workpiece and a grinding wheel. In order to prevent machining accuracy and efficiency from being deteriorated as a result of such a dynamic pressure causing the workpiece to be displaced relative to the grinding wheel, it is contemplated to release the dynamic pressure by providing grooves on a grinding surface of the grinding wheel.